Chlorine → HCID 178456690, Verbindung

127 g of 1-isopropyl-3-hydroxy-1,2,4-triazole and 276 ml of triethylamine are dissolved in 1200 ml of absolute alcohol. The solution turns cloudy yellow. While cooling (26° to 30°C), 106.5 g of chlorine (dried by concentrated sulphuric acid) are passed in within 30 minutes. In the process, the yellow solution initially becomes clear. Subsequently triethylamine hydrochloride precipitates as crystalline product, which is filtered off after stirring for 1 further hour. The filtrate is concentrated to dryness in a rotary evaporator. The brown residue is dissolved in 1 liter of water and 1 liter of ether. The mixture is extracted and separated in a separating funnel. The aqueous phase is extracted three times with 500 ml of ether on each occasion. The combined ether phases are dried over sodium sulphate, the drying agent is filtered off and the filtrate is concentrated to dryness. The light brown residue is dissolved in 500 ml of carbon tetrachloride containing activated charcoal, whereupon the mother liquor is concentrated to 1/3 of its volume and then cooled. The active substance crystallises out and is dried in vacuo for 15 hours at 60°C/15 mm Hg. Yield: 96.3 g (60 % of theory); m.p. : 103°-105°C.